U067D code meaning
Lost Communication With Fan 4
Network system Generic code U06xx codes Check engine light
What U067D means
U067D is meant for a fourth cooling fan with its own network interface that has stopped answering. Four electrically commanded fans are rare. No manufacturer documents U067D publicly: GM's 2025 diesel table 25OBDG04B ends at fan 3, and the engines in GM's 23OBDG07 and 24OBDG07, which do have a fourth LIN fan, report it with the GM-specific code U112B once its response frame ECM_LIN3_CFM4_RSP has been missed three times, maturing over two trips. LIN suits such small motor nodes, and cooling fan motors are a classic application. If fan 4 is wired conventionally, its faults appear as P2C3E to P2C40 for the control circuit and P2C42 for performance. Losing one of four fans mostly shows when cooling demand is high.
U067D at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U067D
- Temperature climbs in traffic or under heavy load
- Warning light depending on manufacturer
- Fan 4 does not run
Common causes of U067D
- Most likelyBus wire to fan 4 damaged
- PossibleFan 4 power feed or ground interrupted
- PossibleFan 4 electronics or motor failed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cooling fan 4Vehicle bus wiring
What each part of U067D means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 7D | The exact fault in that area. |
What to do next
- Note U067D and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U067D
What does U067D mean?
U067D means "Lost Communication With Fan 4". U067D is meant for a fourth cooling fan with its own network interface that has stopped answering. It is a generic code, so it means the same on every make.
Is it safe to drive with U067D?
Drive gently and only to a workshop. With U067D the car can go into limp mode (reduced power) to protect itself.
Will U067D fail an emissions test?
Yes, it can. U067D is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is U067D to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U067D clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.